Do not attempt to send to unregistered users when using CDS flag.

CDS is slow, and unregistered users will always trigger a CDS lookup on
send (since we can't get their UUID).

This starts skipping sends to unregistered users and shortens the time
window to do a full CDS lookup from every 12 hours to every 6 hours.

app/src/main/java/org/thoughtcrime/securesms/contacts/sync/DirectoryHelper.java

@@ -38,6 +38,7 @@ import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.notifications.NotificationChannels;
 import org.thoughtcrime.securesms.permissions.Permissions;
 import org.thoughtcrime.securesms.phonenumbers.PhoneNumberFormatter;
+import org.thoughtcrime.securesms.recipients.RecipientDetails;
 import org.thoughtcrime.securesms.registration.RegistrationUtil;
 import org.thoughtcrime.securesms.storage.StorageSyncHelper;
 import org.thoughtcrime.securesms.recipients.Recipient;
@@ -92,61 +93,35 @@ public class DirectoryHelper {
       return;
     }
 
-    Stopwatch         stopwatch         = new Stopwatch("full");
     RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
     Set<String>       databaseNumbers   = sanitizeNumbers(recipientDatabase.getAllPhoneNumbers());
     Set<String>       systemNumbers     = sanitizeNumbers(ContactAccessor.getInstance().getAllContactsWithNumbers(context));
-    Set<String>       allNumbers        = SetUtil.union(databaseNumbers, systemNumbers);
 
-    DirectoryResult result;
+    refreshNumbers(context, databaseNumbers, systemNumbers, notifyOfNewUsers);
-
-    if (FeatureFlags.cds()) {
-      result = ContactDiscoveryV2.getDirectoryResult(context, databaseNumbers, systemNumbers);
-    } else {
-      result = ContactDiscoveryV1.getDirectoryResult(databaseNumbers, systemNumbers);
-    }
-
-    stopwatch.split("network");
-
-    if (result.getNumberRewrites().size() > 0) {
-      Log.i(TAG, "[getDirectoryResult] Need to rewrite some numbers.");
-      recipientDatabase.updatePhoneNumbers(result.getNumberRewrites());
-    }
-
-    Map<RecipientId, String> uuidMap       = recipientDatabase.bulkProcessCdsResult(result.getRegisteredNumbers());
-    Set<String>              activeNumbers = result.getRegisteredNumbers().keySet();
-    Set<RecipientId>         activeIds     = uuidMap.keySet();
-    Set<RecipientId>         inactiveIds   = Stream.of(allNumbers)
-                                                   .filterNot(activeNumbers::contains)
-                                                   .filterNot(n -> result.getNumberRewrites().containsKey(n))
-                                                   .map(recipientDatabase::getOrInsertFromE164)
-                                                   .collect(Collectors.toSet());
-
-    recipientDatabase.bulkUpdatedRegisteredStatus(uuidMap, inactiveIds);
-
-    updateContactsDatabase(context, activeIds, true, result.getNumberRewrites());
-
-    if (TextSecurePreferences.isMultiDevice(context)) {
-      ApplicationDependencies.getJobManager().add(new MultiDeviceContactUpdateJob());
-    }
-
-    if (TextSecurePreferences.hasSuccessfullyRetrievedDirectory(context) && notifyOfNewUsers) {
-      Set<RecipientId>  existingSignalIds = new HashSet<>(recipientDatabase.getRegistered());
-      Set<RecipientId>  existingSystemIds = new HashSet<>(recipientDatabase.getSystemContacts());
-      Set<RecipientId>  newlyActiveIds    = new HashSet<>(activeIds);
-
-      newlyActiveIds.removeAll(existingSignalIds);
-      newlyActiveIds.retainAll(existingSystemIds);
-
-      notifyNewUsers(context, newlyActiveIds);
-    } else {
-      TextSecurePreferences.setHasSuccessfullyRetrievedDirectory(context, true);
-    }
 
     StorageSyncHelper.scheduleSyncForDataChange();
+  }
 
-    stopwatch.split("disk");
+  @WorkerThread
-    stopwatch.stop(TAG);
+  public static void refreshDirectoryFor(@NonNull Context context, @NonNull List<Recipient> recipients, boolean notifyOfNewUsers) throws IOException {
+    RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
+
+    for (Recipient recipient : recipients) {
+      if (recipient.hasUuid() && !recipient.hasE164()) {
+        if (isUuidRegistered(context, recipient)) {
+          recipientDatabase.markRegistered(recipient.getId(), recipient.requireUuid());
+        } else {
+          recipientDatabase.markUnregistered(recipient.getId());
+        }
+      }
+    }
+
+    Set<String> numbers = Stream.of(recipients)
+                                .filter(Recipient::hasE164)
+                                .map(Recipient::requireE164)
+                                .collect(Collectors.toSet());
+
+    refreshNumbers(context, numbers, numbers, notifyOfNewUsers);
   }
 
   @WorkerThread
@@ -231,6 +206,61 @@ public class DirectoryHelper {
     return newRegisteredState;
   }
 
+  @WorkerThread
+  private static void refreshNumbers(@NonNull Context context, @NonNull Set<String> databaseNumbers, @NonNull Set<String> systemNumbers, boolean notifyOfNewUsers) throws IOException {
+    RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
+    Set<String>       allNumbers        = SetUtil.union(databaseNumbers, systemNumbers);
+
+    if (allNumbers.isEmpty()) {
+      Log.w(TAG, "No numbers to refresh!");
+      return;
+    }
+
+    DirectoryResult result;
+
+    if (FeatureFlags.cds()) {
+      result = ContactDiscoveryV2.getDirectoryResult(context, databaseNumbers, systemNumbers);
+    } else {
+      result = ContactDiscoveryV1.getDirectoryResult(databaseNumbers, systemNumbers);
+    }
+
+    if (result.getNumberRewrites().size() > 0) {
+      Log.i(TAG, "[getDirectoryResult] Need to rewrite some numbers.");
+      recipientDatabase.updatePhoneNumbers(result.getNumberRewrites());
+    }
+
+    Map<RecipientId, String> uuidMap       = recipientDatabase.bulkProcessCdsResult(result.getRegisteredNumbers());
+    Set<String>              activeNumbers = result.getRegisteredNumbers().keySet();
+    Set<RecipientId>         activeIds     = uuidMap.keySet();
+    Set<RecipientId>         inactiveIds   = Stream.of(allNumbers)
+                                                   .filterNot(activeNumbers::contains)
+                                                   .filterNot(n -> result.getNumberRewrites().containsKey(n))
+                                                   .map(recipientDatabase::getOrInsertFromE164)
+                                                   .collect(Collectors.toSet());
+
+    recipientDatabase.bulkUpdatedRegisteredStatus(uuidMap, inactiveIds);
+
+    updateContactsDatabase(context, activeIds, true, result.getNumberRewrites());
+
+    if (TextSecurePreferences.isMultiDevice(context)) {
+      ApplicationDependencies.getJobManager().add(new MultiDeviceContactUpdateJob());
+    }
+
+    if (TextSecurePreferences.hasSuccessfullyRetrievedDirectory(context) && notifyOfNewUsers) {
+      Set<RecipientId>  existingSignalIds = new HashSet<>(recipientDatabase.getRegistered());
+      Set<RecipientId>  existingSystemIds = new HashSet<>(recipientDatabase.getSystemContacts());
+      Set<RecipientId>  newlyActiveIds    = new HashSet<>(activeIds);
+
+      newlyActiveIds.removeAll(existingSignalIds);
+      newlyActiveIds.retainAll(existingSystemIds);
+
+      notifyNewUsers(context, newlyActiveIds);
+    } else {
+      TextSecurePreferences.setHasSuccessfullyRetrievedDirectory(context, true);
+    }
+  }
+
+
   private static boolean isUuidRegistered(@NonNull Context context, @NonNull Recipient recipient) throws IOException {
     try {
       ProfileUtil.retrieveProfile(context, recipient, SignalServiceProfile.RequestType.PROFILE).get(10, TimeUnit.SECONDS);

app/src/main/java/org/thoughtcrime/securesms/jobs/ProfileKeySendJob.java

@@ -56,7 +56,7 @@ public class ProfileKeySendJob extends BaseJob {
       throw new AssertionError("Do not send profile keys directly for GV2");
     }
 
-    List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(conversationRecipient.getParticipants()).map(Recipient::getId).toList()
+    List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(RecipientUtil.getEligibleForSending(conversationRecipient.getParticipants())).map(Recipient::getId).toList()
                                                                    : Stream.of(conversationRecipient.getId()).toList();
 
     recipients.remove(Recipient.self().getId());

app/src/main/java/org/thoughtcrime/securesms/jobs/PushGroupSendJob.java

@@ -19,6 +19,7 @@ import org.thoughtcrime.securesms.database.GroupReceiptDatabase.GroupReceiptInfo
 import org.thoughtcrime.securesms.database.MessageDatabase;
 import org.thoughtcrime.securesms.database.MmsDatabase;
 import org.thoughtcrime.securesms.database.NoSuchMessageException;
+import org.thoughtcrime.securesms.database.RecipientDatabase;
 import org.thoughtcrime.securesms.database.documents.IdentityKeyMismatch;
 import org.thoughtcrime.securesms.database.documents.NetworkFailure;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
@@ -38,6 +39,7 @@ import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.recipients.RecipientUtil;
 import org.thoughtcrime.securesms.transport.RetryLaterException;
 import org.thoughtcrime.securesms.transport.UndeliverableMessageException;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.GroupUtil;
 import org.whispersystems.libsignal.util.Pair;
 import org.whispersystems.libsignal.util.guava.Optional;
@@ -195,7 +197,13 @@ public final class PushGroupSendJob extends PushSendJob {
       List<Pair<RecipientId, Boolean>> successUnidentifiedStatus = Stream.of(successes).map(result -> new Pair<>(findId(result.getAddress(), idByE164, idByUuid), result.getSuccess().isUnidentified())).toList();
       Set<RecipientId>                 successIds                = Stream.of(successUnidentifiedStatus).map(Pair::first).collect(Collectors.toSet());
       List<NetworkFailure>             resolvedNetworkFailures   = Stream.of(existingNetworkFailures).filter(failure -> successIds.contains(failure.getRecipientId(context))).toList();
-      List<IdentityKeyMismatch>        resolvedIdentityFailures = Stream.of(existingIdentityMismatches).filter(failure -> successIds.contains(failure.getRecipientId(context))).toList();
+      List<IdentityKeyMismatch>        resolvedIdentityFailures  = Stream.of(existingIdentityMismatches).filter(failure -> successIds.contains(failure.getRecipientId(context))).toList();
+      List<Recipient>                  unregisteredRecipients    = Stream.of(results).filter(SendMessageResult::isUnregisteredFailure).map(result -> Recipient.externalPush(context, result.getAddress())).toList();
+
+      RecipientDatabase recipientDatabase = DatabaseFactory.getRecipientDatabase(context);
+      for (Recipient unregistered : unregisteredRecipients) {
+        recipientDatabase.markUnregistered(unregistered.getId());
+      }
 
       for (NetworkFailure resolvedFailure : resolvedNetworkFailures) {
         database.removeFailure(messageId, resolvedFailure);
@@ -366,7 +374,10 @@ public final class PushGroupSendJob extends PushSendJob {
     List<GroupReceiptInfo> destinations = DatabaseFactory.getGroupReceiptDatabase(context).getGroupReceiptInfo(messageId);
 
     if (!destinations.isEmpty()) {
-      return Stream.of(destinations).map(GroupReceiptInfo::getRecipientId).map(Recipient::resolved).toList();
+        return RecipientUtil.getEligibleForSending(Stream.of(destinations)
+                                                         .map(GroupReceiptInfo::getRecipientId)
+                                                         .map(Recipient::resolved)
+                                                         .toList());
     }
 
     List<Recipient> members = Stream.of(DatabaseFactory.getGroupDatabase(context)
@@ -377,8 +388,8 @@ public final class PushGroupSendJob extends PushSendJob {
     if (members.size() > 0) {
       Log.w(TAG, "No destinations found for group message " + groupId + " using current group membership");
     }
-    
+
-    return members;
+    return RecipientUtil.getEligibleForSending(members);
   }
 
   public static class Factory implements Job.Factory<PushGroupSendJob> {

app/src/main/java/org/thoughtcrime/securesms/jobs/PushGroupSilentUpdateSendJob.java

@@ -11,6 +11,7 @@ import com.google.protobuf.InvalidProtocolBufferException;
 
 import org.signal.storageservice.protos.groups.local.DecryptedGroup;
 import org.thoughtcrime.securesms.crypto.UnidentifiedAccessUtil;
+import org.thoughtcrime.securesms.database.RecipientDatabase;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
 import org.thoughtcrime.securesms.groups.GroupId;
 import org.thoughtcrime.securesms.jobmanager.Data;
@@ -23,6 +24,7 @@ import org.thoughtcrime.securesms.recipients.RecipientId;
 import org.thoughtcrime.securesms.recipients.RecipientUtil;
 import org.thoughtcrime.securesms.transport.RetryLaterException;
 import org.thoughtcrime.securesms.util.Base64;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.SignalServiceMessageSender;
 import org.whispersystems.signalservice.api.crypto.UnidentifiedAccessPair;
@@ -75,7 +77,15 @@ public final class PushGroupSilentUpdateSendJob extends BaseJob {
     Set<RecipientId> recipients = Stream.concat(Stream.of(memberUuids), Stream.of(pendingUuids))
                                         .filter(uuid -> !UuidUtil.UNKNOWN_UUID.equals(uuid))
                                         .filter(uuid -> !Recipient.self().getUuid().get().equals(uuid))
-                                        .map(uuid -> RecipientId.from(uuid, null))
+                                        .map(uuid -> Recipient.externalPush(context, uuid, null, false))
+                                        .filter(recipient -> {
+                                          if (FeatureFlags.cds()) {
+                                            return recipient.getRegistered() != RecipientDatabase.RegisteredState.NOT_REGISTERED;
+                                          } else {
+                                            return true;
+                                          }
+                                        })
+                                        .map(Recipient::getId)
                                         .collect(Collectors.toSet());
 
     MessageGroupContext.GroupV2Properties properties   = groupMessage.requireGroupV2Properties();

app/src/main/java/org/thoughtcrime/securesms/jobs/ReactionSendJob.java

@@ -75,7 +75,7 @@ public class ReactionSendJob extends BaseJob {
       throw new AssertionError("We have a message, but couldn't find the thread!");
     }
 
-    List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(conversationRecipient.getParticipants()).map(Recipient::getId).toList()
+    List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(RecipientUtil.getEligibleForSending(conversationRecipient.getParticipants())).map(Recipient::getId).toList()
                                                                    : Stream.of(conversationRecipient.getId()).toList();
 
     recipients.remove(Recipient.self().getId());

app/src/main/java/org/thoughtcrime/securesms/jobs/RemoteDeleteSendJob.java

@@ -65,7 +65,7 @@ public class RemoteDeleteSendJob extends BaseJob {
       throw new AssertionError("We have a message, but couldn't find the thread!");
     }
 
-    List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(conversationRecipient.getParticipants()).map(Recipient::getId).toList()
+    List<RecipientId> recipients = conversationRecipient.isGroup() ? Stream.of(RecipientUtil.getEligibleForSending(conversationRecipient.getParticipants())).map(Recipient::getId).toList()
                                                                    : Stream.of(conversationRecipient.getId()).toList();
 
     recipients.remove(Recipient.self().getId());

app/src/main/java/org/thoughtcrime/securesms/jobs/TypingSendJob.java

@@ -9,6 +9,7 @@ import com.annimon.stream.Stream;
 import org.thoughtcrime.securesms.crypto.UnidentifiedAccessUtil;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
 import org.thoughtcrime.securesms.database.GroupDatabase;
+import org.thoughtcrime.securesms.database.RecipientDatabase;
 import org.thoughtcrime.securesms.dependencies.ApplicationDependencies;
 import org.thoughtcrime.securesms.jobmanager.Data;
 import org.thoughtcrime.securesms.jobmanager.Job;
@@ -16,6 +17,7 @@ import org.thoughtcrime.securesms.jobmanager.impl.NetworkConstraint;
 import org.thoughtcrime.securesms.logging.Log;
 import org.thoughtcrime.securesms.recipients.Recipient;
 import org.thoughtcrime.securesms.recipients.RecipientUtil;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.CancelationException;
@@ -104,7 +106,9 @@ public class TypingSendJob extends BaseJob {
       groupId    = Optional.of(recipient.requireGroupId().getDecodedId());
     }
 
-    recipients = Stream.of(recipients).map(Recipient::resolve).toList();
+    recipients = RecipientUtil.getEligibleForSending(Stream.of(recipients)
+                                                           .map(Recipient::resolve)
+                                                           .toList());
 
     SignalServiceMessageSender             messageSender      = ApplicationDependencies.getSignalServiceMessageSender();
     List<SignalServiceAddress>             addresses          = RecipientUtil.toSignalServiceAddressesFromResolved(context, recipients);

app/src/main/java/org/thoughtcrime/securesms/recipients/RecipientUtil.java

@@ -7,6 +7,7 @@ import androidx.annotation.Nullable;
 import androidx.annotation.WorkerThread;
 
 import com.annimon.stream.Stream;
+import com.google.android.gms.common.Feature;
 
 import org.thoughtcrime.securesms.contacts.sync.DirectoryHelper;
 import org.thoughtcrime.securesms.database.DatabaseFactory;
@@ -29,6 +30,7 @@ import org.whispersystems.signalservice.api.push.SignalServiceAddress;
 
 import java.io.IOException;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 public class RecipientUtil {
@@ -38,7 +40,8 @@ public class RecipientUtil {
   /**
    * This method will do it's best to craft a fully-populated {@link SignalServiceAddress} based on
    * the provided recipient. This includes performing a possible network request if no UUID is
-   * available.
+   * available. If the request to get a UUID fails, the exception is swallowed an an E164-only
+   * recipient is returned.
    */
   @WorkerThread
   public static @NonNull SignalServiceAddress toSignalServiceAddressBestEffort(@NonNull Context context, @NonNull Recipient recipient) {
@@ -53,7 +56,7 @@ public class RecipientUtil {
   /**
    * This method will do it's best to craft a fully-populated {@link SignalServiceAddress} based on
    * the provided recipient. This includes performing a possible network request if no UUID is
-   * available.
+   * available. If the request to get a UUID fails, an IOException is thrown.
    */
   @WorkerThread
   public static @NonNull SignalServiceAddress toSignalServiceAddress(@NonNull Context context, @NonNull Recipient recipient)
@@ -79,25 +82,27 @@ public class RecipientUtil {
   public static @NonNull List<SignalServiceAddress> toSignalServiceAddresses(@NonNull Context context, @NonNull List<RecipientId> recipients)
       throws IOException
   {
-    List<SignalServiceAddress> addresses = new ArrayList<>(recipients.size());
+    return toSignalServiceAddressesFromResolved(context, Recipient.resolvedList(recipients));
-
-    for (RecipientId id : recipients) {
-      addresses.add(toSignalServiceAddress(context, Recipient.resolved(id)));
-    }
-
-    return addresses;
   }
 
   public static @NonNull List<SignalServiceAddress> toSignalServiceAddressesFromResolved(@NonNull Context context, @NonNull List<Recipient> recipients)
       throws IOException
   {
-    List<SignalServiceAddress> addresses = new ArrayList<>(recipients.size());
+    if (FeatureFlags.cds()) {
+      List<Recipient> recipientsWithoutUuids = Stream.of(recipients)
+                                                     .map(Recipient::resolve)
+                                                     .filterNot(Recipient::hasUuid)
+                                                     .toList();
 
-    for (Recipient recipient : recipients) {
+      if (recipientsWithoutUuids.size() > 0) {
-      addresses.add(toSignalServiceAddress(context, recipient));
+        DirectoryHelper.refreshDirectoryFor(context, recipientsWithoutUuids, false);
+      }
     }
 
-    return addresses;
+    return Stream.of(recipients)
+                 .map(Recipient::resolve)
+                 .map(r -> new SignalServiceAddress(r.getUuid().orNull(), r.getE164().orNull()))
+                 .toList();
   }
 
   public static boolean isBlockable(@NonNull Recipient recipient) {
@@ -105,6 +110,16 @@ public class RecipientUtil {
     return resolved.isPushGroup() || resolved.hasServiceIdentifier();
   }
 
+  public static List<Recipient> getEligibleForSending(@NonNull List<Recipient> recipients) {
+    if (FeatureFlags.cds()) {
+      return Stream.of(recipients)
+                   .filter(r -> r.getRegistered() != RegisteredState.NOT_REGISTERED)
+                   .toList();
+    } else {
+      return recipients;
+    }
+  }
+
   /**
    * You can call this for non-groups and not have to handle any network errors.
    */

app/src/main/java/org/thoughtcrime/securesms/service/DirectoryRefreshListener.java

@@ -13,7 +13,7 @@ import java.util.concurrent.TimeUnit;
 
 public class DirectoryRefreshListener extends PersistentAlarmManagerListener {
 
-  private static final long INTERVAL = TimeUnit.HOURS.toMillis(12);
+  private static final long INTERVAL = TimeUnit.HOURS.toMillis(6);
 
   @Override
   protected long getNextScheduledExecutionTime(Context context) {

app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java

@@ -59,7 +59,7 @@ public final class FeatureFlags {
   private static final String GROUPS_V2_JOIN_VERSION     = "android.groupsv2.joinVersion";
   private static final String GROUPS_V2_LINKS_VERSION    = "android.groupsv2.manageGroupLinksVersion";
   private static final String GROUPS_V2_CAPACITY         = "global.groupsv2.maxGroupSize";
-  private static final String CDS                        = "android.cds.4";
+  private static final String CDS_VERSION                = "android.cdsVersion";
   private static final String INTERNAL_USER              = "android.internalUser";
   private static final String MENTIONS                   = "android.mentions";
   private static final String VERIFY_V2                  = "android.verifyV2";
@@ -77,7 +77,7 @@ public final class FeatureFlags {
       GROUPS_V2_CAPACITY,
       GROUPS_V2_JOIN_VERSION,
       GROUPS_V2_LINKS_VERSION,
-      CDS,
+      CDS_VERSION,
       INTERNAL_USER,
       USERNAMES,
       MENTIONS,
@@ -106,7 +106,7 @@ public final class FeatureFlags {
       GROUPS_V2_CREATE,
       GROUPS_V2_JOIN_VERSION,
       VERIFY_V2,
-      CDS
+      CDS_VERSION
   );
 
   /**
@@ -266,7 +266,7 @@ public final class FeatureFlags {
 
   /** Whether or not to use the new contact discovery service endpoint, which supports UUIDs. */
   public static boolean cds() {
-    return getBoolean(CDS, false);
+    return getVersionFlag(CDS_VERSION) == VersionFlag.ON;
   }
 
   /** Whether or not we allow mentions send support in groups. */

libsignal/service/src/main/java/org/whispersystems/signalservice/api/SignalServiceAccountManager.java

@@ -368,6 +368,10 @@ public class SignalServiceAccountManager {
   public Map<String, UUID> getRegisteredUsers(KeyStore iasKeyStore, Set<String> e164numbers, String mrenclave)
       throws IOException, Quote.InvalidQuoteFormatException, UnauthenticatedQuoteException, SignatureException, UnauthenticatedResponseException
   {
+    if (e164numbers.isEmpty()) {
+      return Collections.emptyMap();
+    }
+
     try {
       String                         authorization = this.pushServiceSocket.getContactDiscoveryAuthorization();
       Map<String, RemoteAttestation> attestations  = RemoteAttestationUtil.getAndVerifyMultiRemoteAttestation(pushServiceSocket,